Machine Language

A computer is an electronic machine that can
recognize/follow instruction written in binary form, i.e. using only 0s and 1s.
Computer’s natural language is machine language, which can directly understand
by it. This language is not portable and it is machine dependent. A program
written in 1s and 0s is called Machine language.  For a specific operation binary code is used
in machine language. A set of Instructions in binary pattern is associated with
each computer. It is difficult to communicate with a computer in terms of 1s
and 0s.

Assembly Language

In assembly language binary bits
are used and it is a machine language. The programmer can use English like
words as commands that can be easily interpreted by the programmer. The
computer manufacturers started providing English like words abbreviated as mnemonics.
The program contains alphanumeric symbols instead of 1s and 0s.

In assembly language, machine
operations are represented by mnemonic codes (such as ADD, MUL, etc.) and
symbolic names that specify the memory address. Each instruction of an assembly
language contains operation code byte and operand byte/s. 

Consider the following
example 

                        Example        

MOV X, 10 

                        MOV
Y, 20       

ADD X, Y 

Here the mnemonic MOV indicates
an operation to store the value of variable X as 10. The mnemonic ADD implies
addition of the contents of variables X, Y and finally storing the result in
variable X itself.  

High-level Language  

In High level language
instructions are written just like English language words. Here ‘high’ does not
imply that the language is complicated. It means that the language is more
problem solving oriented. Generally, high-level languages are platform independent. 

For example,
a statement to calculate the square of a number can be written in a high-level
language as 

Square = number *
number

The compilers employed to
translate high-level language program to machine language.

2.  What
is a compiler? 

It is software that translates a
program written in a high-level language into machine language.

3.  What
is an interpreter?

While
a compiler converts the whole source code into an equivalent object code or
machine code, the interpreter reads the source code line by line and converts
it into object code (i.e. a code understandable to the machine).

4.  Differentiate
between a compiler and an interpreter. 

The
interpreter reads the source code line by line and converts it into object
code. Whereas a compiler is a software that translates complete program written
in a high-level language into machine language.  

5.  What
is a linker? 

It is a program that links different program modules and
libraries to form a single executable program. It can consist of hundreds of
lines of code. Before the execution of a program, all the modules of the
program and the required libraries are linked together using a software called
a linker.

6.  What
is a loader?

It is used to load and relocate
an executable program in the main memory during execution.

7.  Explain
the internal working of Python in brief. 

The Python interpreter performs
the following steps to execute a

Python program or run a set of instructions in
interactive mode  

STEP 1: The interpreter reads a
Python code or instruction. Then it verifies that the instruction is well
formatted, i.e. it checks the syntax of each line. If it encounters any error,
it immediately halts the translation and shows an error message.  

STEP 2: If there is no error,
i.e. if the Python instruction or code is well formatted then the interpreter
translates it into its equivalent form in low level language called “Byte Code”. Thus, after successful
execution of Python script or code, it is completely translated into byte
code. 

STEP 3: Byte code is sent to
the Python Virtual Machine (PVM). Here
again the byte code is executed on PVM. If
an error occurs during this execution then the execution is halted with an
error message. 

8. Describe the memory unit of a computer system in brief.

Internal memory: It refers to the set
of registers confined within the CPU. These registers hold temporary
data/results when a computation is in progress. 

Primary memory: It is a storage area in which all the programs are
fetched from secondary memory and executed 
 

Secondary memory: It is known as external memory or storage
memory. Programs and data are stored here for the long term. Hard disk,
floppy disk, CDs, DVDs and magnetic tapes are different forms of secondary
memory.